dumb and simple questions from a noob

I'm brand new to this sub and have some extremely dumb questions (I'm talking i was about to buy jbl 9.1 soundbar for 1500 before i found this sub lol). ive tried to answer my own questions by digging around the sub but honestly am still a bit lost:

1. if you have an actual surround sound system (5.1 or more), how on earth do you manage all those cables? are newer setups wireless (as in there's only power cords?). i'm trying to figure out if i could even have a nice audio setup without cables running all around my room which is a no go for me due to the gf. any basic info / website links would be great

2. tv aside (not willing to do projector at this point in my life), how much does a nice audio setup cost (mid-range, not entry level but not ultra high end)? I'd be willing to spend 3k on a nice system (including receiver) and build as i go. any suggestions on what to priortize would be great. for some context, I have around a 12x12 space for my media setup. and again, i don't really care about aestehtic but it cant be an eyesore

3. any general websites about the basics of home theatre setup would be awesome...really trying to dive deep. i've been producing music for many years and my favorite part about it is being a gear junkie....and i'm becoming a gear junkie all over again for all this home theatre equipment....this sub is awesome

thanks in advance.